BETA | ANIMATION
CHARACTER BUILDING: NORMAL MAPPING
“There has been a clear progression from the movie special effects space where cloth was a purely offline process, to games, where the algorithms have been specially modified to run in a considerably smaller time slice,” concludes Bowell. A generic challenge, not directly related to cloth but one that impacts it, is that of content generation. “Any modern character driven game has a number of options when it comes to clothing,” explains Bowell. “The first option is to model the cloth as part of the character’s skin and have animators animate the cloth. This option adds a considerable number of new clothing animations for each character, the number of which scales up quickly. Often what happens is only a single garment gets animated – for example a tie or a cloak – and as the animations are cyclical, the results typically don’t look very realistic.” The second option is to simulate the cloth with a real-time system such as Havok Cloth. In this case once an artist has rigged up the properties of Havok Cloth, the simulation can take care of the rest. This option means that the artist still has a lot of control over how the cloth looks and feels but the burden of creating many animations is no longer necessary. A sizable challenge in the cloth space is to create material that looks good at all times. “The range and speed of movement that often goes on within a game can easily break the illusion, add to this that you are often not animating to a set camera, so the challenge is to make a cloth solution that can be honed, constrained and posed by animators. Creating real-world physics will only get you so far,” offers Ninja Theory’s Adcock. BIG RIG Over in the rigging space, a paradigm shift is in place that is seeing the order of process made more dynamic. “One of the biggest issues we have with rigging is that it’s traditionally a rather linear process. In the past, starting the rigging process pretty much meant the character model had to be complete,” says Jones, highlighting a fact that can cause substantial problems when a client needs to change or swap out a character at the last minute. It also meant that rigging would tend to happen somewhat late on in the schedule. Things are changing, however. “By taking advantage of proxies and wrapping techniques, we’re able to work on a character’s rig entirely independently from
Below: Mick Morris of Audiomotion, Imagination Studio’s Nataska Statham, and Image Metric’s Nick Ramsay
30 | APRIL 2011
ONE FOR ALL Steamrolling the various character animation technologies into one process is encouraging, but as smaller studios making low-budget games rise to prominence, the tech needs to become accessible. Happily, that is already happening. “Motion capture is absolutely becoming more accessible” says Jim Richardson, president and CTO at mocap hardware outfit NaturalPoint. “Over the past several years, complete systems have emerged that cost less than a used car, opening the technology to a completely new audience.”
the model and then apply the model to the rig at a much later date,” says Realtime UK CG director Jones. “This allows us to invest a lot more time developing and refining each rig in tandem with the characters development.” Skinning is another area where new developments are helping developers offer greater realism with better efficiency. “One very exciting recent development has been advances in the ability to model skin interaction,” suggests Adcock. “For example, when you move your chin down to your chest the skin around your body is being stretched and folded in lots of different places around your neck, chin and the upper chest. We can now model all of this, making things just that little more lifelike and much more believable.”
The challenge is to make a cloth solution that can be constrained by animators. Creating real-world physics will only get you so far. Stuart Adcock, Ninja Theory PIPING UP Charcater animation pipelines are also changing, responding to the consumer expectation for greater number of believable characters in-game and on-screen. Perhaps nobody knows more about this than The Creative Assembly, whose famously busy battlefields have become a trademark of the Total War series. “For Total War, it’s imperative that we keep the pipeline and workflow as simple as possible,” reveals Alston. “Because the series deals with thousands of characters on screen, we are imposed with very tight constraints on our characters, plus the breadth and depth required for the games means we are dealing with thousands of animations. Not including cinematics, Total War: Shogun 2 featured just under 3,000 in-game character animations. Each was created in 3ds Max, before being exported into MotionBuilder, in which the team created the animation control rig. Dependent on the character and situation, Creative Assembly then either hand keys the animation, or imports the mocap into MotionBuilder. 3D animation tool providers have responded to this trend in kind, with companies like Autodesk showing a renewed focus on developing real-time, mocap-centric tools, as evidenced in recent versions of Maya and 3ds Max, and their upcoming release of MotionBuilder 2012. “The combined effect of these trends is a decreasing barrier to entry into the world of motion capture for smaller studios and independent animators,” says Richardson. As the industry evolves the democratisation of mocap and character animation is becoming a reality. Soon even microstudios could reap the benefits.